The Death of Stars

Now let’s consider what happens to stars as they approach the end of their lives. The final destination of a star depends entirely on its mass. Low-mass stars (like the sun) will shed their outer layers as planetary nebulae while their cores collapse to form a white dwarf. Higher mass stars ultimately explode in a tremendous burst of energy called a supernova, leaving behind a cloud of debris and a core that has transformed into a bizarre new kind of object - either a neutron star or a black hole.
First, let’s consider the death of low-mass stars. Read 22.4 Further Evolution of Stars to learn about the final stages of a sun-like star’s life and how it can eventually become a planetary nebula.
Watch the video Planetary Nebula Gallery and explore the gallery for yourself.
Now let’s explore how the core of a low-mass star evolves into a white dwarf (and eventually a black dwarf). Read section 23.1 The Death of Low-Mass Stars.
Watch the Kurzgesagt video White Dwarfs for a lovely illustration of the evolution of low-mass stars.
To understand what is happening inside the final collapse of a star’s core, we need to think about the actual atoms of gas within it. Watch the teacher video Compact Objects to see how gravity eventually tears apart the atoms of a dying star.
Now let’s examine what happens to larger stars when they die. Read 23.2 Evolution of Massive Stars: An Explosive Finish to learn about the formation of neutron stars through supernova explosions.
Watch the SciShow video The Supernova of 1054 to learn about one of the rare nearby supernova events from history.
Review 23.3 Supernova Observations to understand the frequency of supernovae in the Milky Way Galaxy, the observation of SN 1987A, and the significance of supernova explosions in the universe.